<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body style="padding: 50px;">
    <div class="calculator">
        <p>结果：<span class="result">0</span></p>
        <div class="input-group">
            <input type="text" value="0" class="num-input">
            <input type="text" value="0" class="num-input">
        </div>
        <div class="btn-group">
            <button data-method="add">+</button>
            <button data-method="sub">-</button>
            <button data-method="mul">*</button>
            <button data-method="div">/</button>
        </div>
    </div>
</body>
</html>